Process of preparing acetylene



Oct. 5, 1937. c. wEiBzzAi-m ET AL 20,527

PROCESS OF PREPARING AGETYLENE Original Filed Feb. 8, 1929 Carl 71/213:zaJm Felix Mill-er INVENTORS ATTORNEYS Reissued Oct. 5, 1937 PATENTOFFICE PROCESS OF PREPARING ACETYLENE Carl Weibezahn and Felix Walter,Knapsack,

near Oologne-on-the-Rhine, Germany, assignors to Aktiengesellschai'ttiir Stickstoffdunger, Cologne-on-the-Rhine, Germany, a. corpora-.

tion

Original No. 1,916,592, dated July 4, 1933, Serial No. 338,433, February8, 1929. Application for reissue June 29, 1935, Serial No. 29,106. .InGermany February 14, 1928 13 Claims. (01. 48-216) The present inventionrelates to a process of preparing acetylene.

It is generally known that in the manufacture of acetylene from calciumcarbide the removal of heat evolved during the process is of greatimportance, because high tem erature causes loss of material and dangerin, working; for this reason the calcium carbide is introduced into 7-10times its weight of water, and this mode of procedure is officiallyprescribed for industrial carbide gas producers. Apart from certainlosses caused by the use of such a relatively large quantity of water,the said procedure has the special disadvantage that the calciumhydroxide which is formed is obtained in a state of mud, which rendersits industrial utilization dimcult; in certain cases the hydroxide evenconstitutes a cum;- bersome waste product. Numerous attempts have beenmade to reduce the proportion of water to be used in producing gas fromthe calcium carbide without loss of material or danger in working. Ithas been proposed to decompose the calcium'carbide with a limitedquantity of water in presence of calcium hydroxide powder the calciumcarbide being brought into contact with the calcium hydroxide whileintroducing such a quantity of water as will prevent an excessive andthereforeinjurious rise of temperature. However, attempts in thisdirection have not given the desired result because it has not beenpossible to absorb the heat evolved during the decomposition of thecalcium carbide 'sufliciently to avoid a dangerous rise of temperatureduring the whole process.

The present invention relates to a simple method by which the problem inquestion may be solved. According to this method there is applied to thecalcium carbide, while it is kept continuously in motion, so much waterin a finely divided form, that there is present inaddition to the amounttheoretically required for producing the gas a further quantity as issuflicient to absorb the heat evolved without a dangerous rise oftemperature. During the process care must be taken that, while the wateris applied, the calcium carbide to be decomposed is simultaneously keptin motion, so that not only is the surface presented to the watercontinually changed and the calcium hydroxideproduced kept uniformlymixed with the remaining calcium carbide but also the temperature iskept uniform throughout the mass by the movement. In this manner it ispossible to absorb the heat, as it is produced, by converting water intosteam ata temperature not exceeding 100 0., the steam escaping alongwith the acetylene evolved. Thus,

a complete yield of acetylene can be produced from the calcium carbidewithout any danger, while there is simultaneously obtained asubstantially dry calcium hydroxide.

' In working the new process, it is not absolutely necessary to add thewater in a finely divided form. For carrying out. the process accordingto the invention, any one of the usual apparatus may be used whichpermits a continuous and thorough mixing of the calcium carbide and atthe same time allows introduction of the water'in a suitable form andremoval of the acetylene. and the calcium hydroxide produced. However, agenerator, as shown in diagrammatic vertical section in the accompanyingdrawing, has proved to be very suitable. Such apparatus is claimed inour copending application Serial -No. 484,112 (now Patent 1,947,120,dated February 13, 1934).

The calcium carbide is conveyed from the storage vessel A to thegenerator D by means of a delivering device B and the screw conveyer C.In this generator is a nwnber of fixed plates F arranged in steps, oneabove the other, By means of stirring arms carried by a vertical shaft Ein the generator, the calcium carbide is caused to pass from plate toplate. The water'is uniformly distributed over the calcium carbide bymeans of the nozzles H mounted above the plates. By

the action of the stirring arms the mass is thordevice. which preventschoking of the outlet pipe by any lime that may be carried along withtheacetylene. The acetylene then lpasses through the cooler K and thewasher L to the place of use. The substantially dry calcium hydroxidewhich falls into the chutes Gis continuously removed by the conveyer Magainst the pressure of the weighted door N.

' Accordingly, in the operation of this process the gaseous productsproduced flow countercurrent to, and in intimate contactwith, all otherconstituents in the reaction chamber; that is to say, the calciumcarbide and water as well as the resulting calcium hydroxidecontinuously advance through the generator in intimate contact with, andin a direction which is countercurrent ylene and substantially drycalcium hydroxide from calcium carbide which comprises moistening amoving body comprising calcium carbide with water at a plurality ofpoints along its path of movement while continuously agitating theconstituents of the moving body, the amount of water employed being onlythat necessary to effect a conversion of the calcium carbideintoacetylene and calcium hydroxide and a reduction of the heat of thereaction to below 100 C. by evaporation of a part of said water.

2. A process as in claim 1 wherein the moving body is given a step bystep advance and water is sprayed thereon at each step.

3. The process for continuously producing acetylene and substantiallydry calcium hydroxide from calcium carbide which comprises directlycontacting a moving body consisting initially of calcium carbide withwater at a plurality of points along its path of movement while continu-25- ously agitating the constituents of the moving body, the amount ofwater employed being only that necessary to efiect a conversion of thecalcium carbide into acetylene and calcium hydroxide and a reduction ofthe heat of reaction to below 100 C. by evaporation of a part of saidwater.

4. The pr cess for continuously producing acetylene i214; substantiallydry calcium hydroxide from alcium carbide'which comprises directly contting a moving body consisting initially of ca cium carbide with wateralong its path of movement while continuously agitating the moving body,the amount of water employed being not more than that necessary toefiect a conversion of the calcium carbide into acetylene and calciumhydroxide and a reduction of the heat of reaction to below 100 C. byevaporation of a part of said water.

5. The process for continuously producing acetylene and substantiallydry calcium hydroxide from calcium carbide, which comprises directlycontacting a moving body consisting initially of calcium carbide withwater along its path of movement whilecontinuously agitating the movingbody, the amount of water employed being not more than that necessary toefiect a conversion of the calcium carbide into acetylene and calciumhydroxide and a reduction of the heat of reaction to below 100 C. byevaporation of a part of said water, and continuously removing thesubstantially dry calcium hydroxide formed by said reaction.

6. A process for continuously producing acetylene and substantially drycalcium hydroxide, which comprises feeding calcium carbide into agenerating zone; adding water directly to the,

material in the generating zone, the amount of water so added beingsubstantially the quantity of water necessary to react with the calciumcarbide and effect a conversion of the latter into\ acetylene andcalcium hydroxide plus a quantity of water adapted to be vaporized andreduce theheat of such reaction so as to avoid a dangerous rise .oftemperature in said generating zone; and,

during the addition of such water, continuously mixing the calciumcarbide and the calcium hydroxide, so that the surface presented to thewater is continually changed and the temperature throughout the materialis kept substantialLv uni form.

ously adding water to said material while the same is advancing, theamount of water employed being sufiicient but not more than the quantityof water required to completely react the calcium carbide and produceacetylene and calcium hydroxide plus the quantity of water required toabsorb suflicient heat evolved by such reaction to avoid a'dangerousrise of temperature within said chamber; and, during the advance of thematerial and the addition of the water, continuously mixing the materialso that the surface thereof presented to the water is continuallychanged and the temperature throughout the material is keptsubstantially uniform.'

8. A process for continuously ylene and substantially dry calciumhydroxide, which comprises continuously feeding calcium carbide into andadvancing the same within a generating chamber continuously sprayingwater directly onto said calcium carbide at a plurality of points withinsaid chamber while said calcium carbide is advancing, the amount ofwater so sprayed being sufiicient but not more than the quantity ofwater required to completely react the calcium carbide and produceacetylene and calcium hydroxide plus the quantity of water required byvaporization thereof to absorb sufficient heat evolved. by suchreactionto avoid a dangerous rise of temperature within said chamber; and,during the addition of the water and the advance of the calcium carbideand the resulting calcium hydroxide, continuously mixing producingacetthe remaining calcium carbide with, the water and the resultingcalcium hydroxide, so that the surface of such material presented to theinflowing water is continually changed and the temperature throughoutthe material is kept substantially uniform. x

9. A process for continuously and simultaneously producing acetylene andsubstantially dry calcium hydroxide, which comprises continuouslyfeeding calcium carbideinto a generating chamber; continuously applyingwater to the calcium carbide in said chamber, the amount of water soapplied being suflicient but not more than the quantity of waterrequired to completely react said calcium carbide and produce acetyleneand calcium hydroxide plus the quantity of water required to absorbsumcient heat evolved by such reaction to avoid' a dangerous rise oftemperature within said chamber; while said water is being, so applied,continuously mixing the resulting mass of calcium carbide, calciumhydroxide and water, to continually change the surface of the mass thatis presented to the water so applied, whereby the temperature throughoutsaid mass is kept substantially uniform and a portion of said water isconverted-into water vapor; and removing water; vapor along withacetylene from said generating chamber.

10. A process for continuously and simultaneously producing acetyleneand substantially dry calcium hydroxide, which comprises continuouslyfeeding calcium carbide'into a generating chamber; continuously applyingwater directly to the cium hydroxide resulting from the reaction of suchwater and calcium carbide, the amount of water so applied beingsufllcient but not more than the quantity of water required to complete-1y react said calcium carbide andproduce acetylene and calcium hydroxideplus the quantity oi water required to absorb sumcient heat evolved bysaid reaction to avoid a dangerous rise or temperature within saidchamber; and, while said water is being so applied, continuouslyadvancing the resulting mass or calcium carbide, calcium hydroxide andwater and continuously mix ing said mass to continually change thesurface or the mass presented to theiniiowing water, whereby thetemperature mass is kept substantially uniform and a portion oi saidwater is converted into steam; and removing steam from said generatingchamber with the acetylene produced in said chamber.

11. A process for continuously and simultaneously producing acetyleneand substantially dry calcium hydroxide, which comprises continuouslyfeeding calcium carbide into a generating chamber; continuously applyingwater directly to the calcium carbide in said chamber, the amount ofwater so applied being suillcient but not more than the quantity ofwater required to completely react said calcium carbide and thereby,produce acetylene and calcium hydroxide plus the quantity of waterrequired to absorb suflicient heat evolved by such reaction to avoid adangerous rise of temperature within said chamber; while said water isbeing applied, continuously advanc-.

ingwithin said chamber the resultingmass of calcium carbide, calciumhydroxide and water and continuously 'mixing said mass to continuchamberin a direction throughout said allychangethesurfaceoisaidmassthatis]:sented to the water so applied, whereby the temperature throughout saidmass is kept substantially uniform and a portion of said water isconverted into steam; and removing acetylene and steam simultaneouslyfrom said generating that is countercurrent to the direction oi' advanceof said mass within said chamber.

12. A process for continuously and simultaneously producing acetyleneand substantially dry calcium hydroxide as claimed in claim 11, whereinsaid resultingmass of calcium carbide, calcium hydroxide and water iscontinuously ad-' vanced downwardly within said chamber, and acetyleneand steam simultaneously flow upwardly within said chamber in adirection counter,- current to the direction of advance of said mass.

13. A process for continuously and simultaneously producing acetyleneand substantially dry calcium hydroxide as claimed in claim 11, whereinsaid resulting mass of calciumicarbide. cal- .cium hydroxide and wateris continuously ad- 'vanced downwardly within said chamber, acetyleneand steam simultaneously 7 now upwardly within said chamber in adirection countercurrent to the direction of advance oi said mass, andthe calcium hydroxide so produced is removed i'rom the bottom end ofsaid chamber.

CARL WEIBIZAHN.

